Mechanism for correcting printing plates



Feb. 17. 1925. 1,526,969

' E. ERICKSSON f MECHANISM FOR CORRECTING PRINTING PLATES Fild Dec. 12,1923 Patented Feb. 17, 1925.

UNITED STATES EMIIt ERICKSSO'N, 01E CHICAGO, ILLINOIS, ASSIGNOB TO WM.A. FIELD COMPANY, OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS.

Application filed December 12, 1923. Serial No. 680,188.

To all whom it may concern: I

Be it known that I, EMIL ERIOKSSON, a citizen of the United States,residing at Chicago, in the county of Cook and State of Illinois, haveinvented certain new and use ful Improvements in Mechanism forCorrooting Printing Plates, of which the following is a specification.

The machine of the present invention is designed for the purpose ofquickly and accurately correcting inequalities in the type surface of aprinting plate prior to the setting up of the plate in a printing press.In-

equalities in the level of the type surface are usually present asaresult of the warping of the metal or other causes, so that such a platerequires correction in order that it will register an even impressionwhen used in printing presses. The means provided in the present machineare. designed to apply pres sure to allportions of the rear surface of atype plate, thereby leveling out the type surface against the level bedof the machine and transferring the inequalities of the rear surface,after which said rear surface may, if desired, be leveled off by planingor like process.

In the drawing:

Figure 1 is a top or plan view of the present machine;

Fig. 2 is a side elevation of the same;

Fig. .3 is an enlarged sectional view of a portion of the pressurecylinder illustrating the projecting pins which afford the actingsurface of the cylinder; and

Fig. 4 is a similar view showing a modified form of thepins.

- The machine comprises a fixed table upon which is slidably mounted abed-plate '11 provided along each edge with a rack 12,

the two racks being in parallel relation. The

upper surface of the bed-plate is a true surface which, in the formshown. is a flat plane, although it might be of evenly curved formationfor the correction of plates do i signed for use on cylinder presses.

To each side of the table is secured an upright standard 13 whichprojects above the table and affords a mounting for a cylinder 14provided at each end with a trunnion 15 carried by a journal block 16working in a slot 17 in the adjacent standard. Each journal block bearsupon a spring 16 which is socketed in the corresponding standard, and

the elevation of the cylinder is regulated at each end by means of aset-screw 18 threaded through the top of the standard. The arrangementis one which maintains the surface of the cylinder in spaced relation tothe surface of the bed plate to permit the printing plates to be mountedupon the bed plate and fed beneath the cylinder, and the latter may beadjusted. within limits, to provide for variations in the standardthickness of different printing plates.

The cylinder is provided at each end with a gear 19 which meshes withthe underlying rack, so that as the bed plate is moved back and forthalong the table, positive rotation will be imparted to the cylinder. Thecylinder comprises at each end a head 20 which is keyed upon a shaft 21,which shaft terminates in the trunnion 15, and the cylinder heads. areunited by a cylinder base wall 22 of lesser radius of curvature than thecylinder heads.

Surrounding the base wall 22 is a cylindrical outer wall 23, the surfaceof which lies flush with the outer edges of the cylinder heads andbetween the two walls, and resting upon the base wall is a cushion layer2% formed of rubber or other like yieldable material. The outer wall isprovided withfa large number of closely spaced bores 25 each of whichaffords a guide for a pin 26, the outer end of which normally protrudesabove the outer wall of the cylinder and the inner end of which isfurnished with an enlarged head 27 which bears against the yieldablecushion, the heads being spaced from one another to afiord displacementarea for the rubber or other like material when the pins are forcedinwardly in varying degrees during the correction process.

In Fig. 4, the construction is in all respects similar save for the factthat the base wall 22 is provided with a plurality of guide apertures 28in radial alignment with the bores 25, and in this case the pins 29 areextended by the provision of tail. pieces 30 which enter the guideapertures 28, coiled springs 31 being interposed which bear against thehead flanges 32. v

In operation a type plat-e33 is laid tight face down upon the bed plate11, and the bed plate is then moved under the cylinder which causes theprotruding pins to bear upon the rear surface of the type plate andimpart compression thereto in such degree as may be required to flattenout any inequalities in the plane of the type surface, whichinequalities are thus transferred to the rear surface of the plate, theprotruding pins meanwbi e yielding locally in varying degree toaccommodate the inequalities thus transferred to the rear surface. Asthe pins yield, they compress the rubber at points in contact with thepin heads and at the same time permit the rubber or like materia tobulge'or protrude into the intervening spaces to accommodate thedistortion, so that the distortions are all accommodated locally whichpermits the correction to be effected without an imposition of extremepressures which might tend to injure the type surface.

In the cylinder of Fig. 4 a similar result is obtained by providing eachof the pins with its own individual spring so that the various pins willyield locally to the degree necessary to accommodate local conditions.

The machine as a whole is one which permits the plates to be rapidly fedthrough the machine from either direction and provides for theimposition of a rolling pressure which can be easily applied by handopera tion rather than by the use of hydraulic or other presses of achaacter heretofore used. The simplicity of the device is one whichparticularly fits it for use in small printing establishments or underconditions where the use of more involved machinery would beundesirable.

I claim: 7

1.. In mechanism for correcting printing plates, the combination of abed plate and a cylinder mounted to apply a rollingpressure between thebed plate and the cylinder, a plurality of contact members outwardlyprotruding from the cylinder, and yieldable means for maintaining thecontact members in normal protruding relation to the cylinder,substantially as described.

2. In mechanism for correcting printing plates, the combination of a bedplate and a cylinder mounted to apply a rolling pressure between the bedplate and the cylinder, a plurality of contact members outwardlyprotruding from the cylinder, and a yieldable cushion bearing'againstthe inner ends of the contact members and normally holding the same inoutwardly protruding po sition, substantially as described.

3. In mechanism for correcting printing plates, the combination of a bedplate and a cylinder mounted to apply rolling pressure between the bedplate and the cylinder, a plurality of contact members outwardlyprotruding from the cylinder, yieldable means for maintaining thecontact members in normal protruding relation to the cylinder,'an'dmeans for varying the spaced relation between thecylinder and the bedplate, substantially as described.

's. In mechanism for correcting printing plates, the combination of abed plate and a cylinder mounted to apply a rolling presbetween thecylinder and the bed plate, substantially as described.

a. In mechanism for correcting printing plates. the combination of a bedplate, a cylinder, entrained mechanism between the bed plate and thecylinder for imparting rotation to the cylinder by the relative movementof the bed plate and cylinder, and yield-ably mounted contact memberscarried by the cylinder and outwardly protruding therefrom,substantially as described.

6. In mechanism for correcting printing plates. the combination of a bedplate, a cylinder, entrained mechanism between the bed plate and thecylinder for imparting rotation to the cylinder by the relative movementof the bed plate and cylinder, yieldably mounted contact members carriedby the cylinder and outwardly protruding there from, and means forvarying the spaced relation between the cylinder and the bed plate.substantially as described.

7. In mechanism for correcting printing and yieldably mounted contactmembers carried by the cylinder and normally protruding from the surfacethereof, substantially as described.

8. In mechanism for correcting printing plates, the combination of aslidably mounted bed plate. a fixedly positioned rotatably mountedcylinder overlying the bed plate, yieldably mounted contact memberscarried by the cylinder and normally protruding from the surfacethereof, and entrained power transmission mechanism between the cylinderand bed plate for positively rota1- ing the cylinder by movements of thebed plate. substantially as described.

9. In mechanism for correcting printing plates. the combination of aslidably mounted bed plate, a fixedly positioned rotatably mountedcylinder overlying the bed plate. yieldably mounted contact memberscarried by 'the cylinder and normally protruding from the surfacethereof, a rack on the bed plate, and an intermeshing gear on thecylinder for rotating the cylinder by movements of the bed plate,substantially as described.

10. In mechanism for correcting printing plates, 'the'combination of atable. standards llfi upwardly extending from the table, a bed plateslidably mounted upon the table and in spaced relation to the surface ofthe cylinder, and a plurality of yieldably mounted contact membersoutwardly protruding from the surface of the cylinder, substantially asdescribed.

11. In mechanism for correcting printing plates, the combination of atable, standards upwardly extending from the table, a bed plateslida-bly mounted upon the table and in spaced relation to the surfaceof the cylinder, a plurality of pins entered through the outer surfaceof the cylinder and nor mally protruding therefrom, and yieldable meansfor normally maintaining said pins in protruding relation, substantiallyas described.

12. In mechanism for correcting printing plates, the combination of atable, standards upwardly extending from the table, a bed plate slidablymounted upon the table and in spaced relation to the surface of thecylinder, a plurality of pins entered through the outer surface of thecylinder and normally protruding therefrom, and a yieldable cushioncarried by the cylinder and underlying the inner ends of said pins andnormally maintaining the same in protruding relation, substantially asdescribed.

EMIL ERICKSSON.

